I keep dried mushrooms in my pantry just for occasions like this one.
Soak in warm water for 15 minutes, drain, rinse, and chop to desired size.

large handful of greens

I used a mache greens mix, but I think kale, chard, or other hearty greens would work beautifully. Make sure to drizzle hearty greens with olive oil and salt & pepper to make sure they wilt during cooking.